


"Experimental"

by orphan_account



Category: Undertale (Video Game)
Genre: Anal Sex, Ecto Breasts, Ecto Vag, Fontcest, M/M, Sex, Smut, Teasing
Language: English
Status: Completed
Published: 2017-02-06
Updated: 2017-02-06
Packaged: 2018-09-22 11:46:26
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 383
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9606308
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: Gaster tries out a new power on Sans.





	

"Hmmm,"Gaster hums sweetly looking at the sight before him,"Do you...like this Sansy?" Sans was laid on his back along with his hands tied behind his back. He was naked with an ecto stomach, pussy, which had a vibrator inside, and the new experimental thing, ecto breasts.

"Yes...fuuuuuck...I love it! Please insert your cock inside me!"Sans gasps out. Gaster chuckles a little before saying?"Not now Sans, I need to see to my...experiment." He gently touches Sans' left breast, and slowly rubs his finger around the nipple. Sans whines needly. Gaster puts his on Sans right nipple and Sans gasps loudly.

Sans begs,"Please more! Give me more! I need it!"Gaster grins as he continues sucking. He lightly bites the nipple and pulls it with his teeth. Sans was turning into pudding under his touch. His loud moans echoed through the room. Gaster sucks on Sans' breast some more before releasing with a popping sound.

Gaster was getting hard already. He wanted to fuck Sans right then and there, shoving his cock up Sans' ass with the vibrator still in his vagina. Gaster lubed his cock without Sans noticing and jumped at the opportunity. Sans screamed from pain and pleasure that shot up his body.

Gaster thrusts in and out at a fast pace, Sans begging for more."This...so fucking...g-good Gaster! Please fuck my harder!"Sans yells. Gaster moans loudly,"You like this Sans? You like it when I fuck your right little ass? Mmm, Sans, you feel so good. Shiiiiiit." Gaster rubs Sans soul uses his magic to fuck Sans in then pussy and Sans literally has is saying incoherent words, saying Gaster's name in between.

Gaster grunts and moans as he nears his climax. "Come inside!"Sans demands,"Come inside me please!"Gaster groans loudly as he comes inside, and Sans loudly moans yes as he squirts all over Gaster. They both pant from their amazing climax, Gaster covered in Sans' sweet juices.

Sans was the first to speak,"Well, Gaster, I'll be happy to oblige if you want to do this...well,"experiment" again." Gaster gives him a weak open mouthed smile,"I'll be happy to do so, Sansy. I think we should rest for a while, we'll clean up later."

**Author's Note:**

> Hoped you demons enjoyed and ✌️!


End file.
